JPH0615701A - Method and apparatus for changing mold for injection molding machine - Google Patents

Abstract

PURPOSE:To facilitate an automatic changing of molds in an unmanned factory or the like, to reduce cost to a great extent, to enhance accuracy in control and to make structure of the mold simple and compact. CONSTITUTION:For changing of a mold 2 for an injection molding machine, characteristic data D2 of a sensor, for instance a pressure sensor 3, to be incorporated in the mold 2 are measured beforehand, and the measured data D2 and identification code D1 of the mold 2 to which the characteristic data D2 are incorporated are stored in a memory. In changing of the mold, characteristic of a control system 5 that processes signals Sd detected from the pressure sensor 3 is corrected, for instance by means of gain correction or zero correction, in accordance with the characteristic data D2 corresponding to the identification code D1 of the mold 2 to be changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for changing a mold of an injection molding machine, which is suitable for automatically changing a mold in an injection molding machine.

[0002]

2. Description of the Related Art Conventionally, when controlling the injection pressure of an injection molding machine, pressure feedback control has been performed based on a pressure detection signal from a pressure sensor provided in an injection cylinder. On the other hand, the detection result of the resin pressure in the mold cavity is useful data in terms of pressure control in the cavity and quality control of molded products, so a pressure sensor is installed in the mold. Pressure (injection pressure) based on the resin pressure in the mold cavity detected from
Feedback control is often performed.

In this case, as the pressure sensor incorporated in the mold, a pressure converting element (crystal element or the like) is used, which is embedded so as to form a part of the mold cavity, and the pressure converting element by pressure is used. The strain amount is converted into a voltage proportional to the strain amount by the strain gauge amplifier.

[0004]

By the way, in recent years, an injection molding system in which an automatic mold changer, an automatic material switching device, and the like are provided together with the injection molding machine is increasing due to the demand for automation and labor saving. In this type of molding system, the pressure sensor also changes each time the mold is replaced, but since the pressure sensor (pressure conversion element) has different characteristics, gain adjustment and zero adjustment are usually performed on the strain gauge amplifier side when the mold is replaced. Making adjustments.

However, in an unmanned factory or the like, since it is unmanned in the first place, it is difficult to perform gain adjustment or zero adjustment at the time of mold replacement, and it is impossible to detect the mold internal pressure and perform precise control based on it. there were. To solve this problem, a strain gauge amplifier may be mounted on each mold to eliminate the difference (variation) in the characteristics of the individual pressure sensors.
On the other hand, it requires a large number of amplifiers corresponding to the number of molds, resulting in a significant cost increase, and since it needs to be installed on each mold side, the configuration becomes complicated in terms of power supply, etc. However, there arises a problem of increasing the size of the entire mold.

The present invention solves the problems existing in the prior art as described above, and easily realizes automatic die replacement in an unmanned factory or the like, and significantly reduces the cost.
An object of the present invention is to provide a mold replacement method and device for an injection molding machine, which can achieve high precision control, simplification of mold structure, and downsizing.

[0007]

A method of exchanging a mold for an injection molding machine according to the present invention is such that, when the mold 2 in the injection molding machine M is replaced, a sensor, for example, a pressure sensor 3 which is incorporated in the mold 2 in advance. Of the characteristic data D2 measured, and the identification code D1 of the mold 2 incorporating the sensor of the characteristic data D2 and the sensor of the characteristic data D2 are stored and correspond to the identification code D1 of the mold 2 to be replaced at the time of mold replacement. The detection signal Sd from the pressure sensor 3 based on the characteristic data D2
It is characterized in that the characteristics of the processing system 5 for processing are corrected, for example, gain correction and zero correction.

The mold exchanging device 1 of the injection molding machine according to the present invention is for implementing the above-mentioned mold exchanging method, and includes the identification code D1 of the mold 2 and the pressure sensor 3 incorporated in the mold 2. A data storage unit 6 for storing the characteristic data D2, and the characteristic data D2 read from the data storage unit 6 at the time of mold replacement.
On the basis of the above, the characteristic correction unit 7 for correcting the characteristics (gain correction and zero correction) of the processing system 5 for processing the detection signal Sd from the pressure sensor 3 is provided.

[0009]

According to the mold replacement method for the injection molding machine and the mold replacement device 1 according to the present invention, first, the characteristic data D2 of the pressure sensor 3 to be used is measured. Then, the measured characteristic data D2 and the identification code D1 of the mold 2 incorporating the sensor of the characteristic data D2 are stored in the data storage unit 6.

On the other hand, at the time of die replacement, the characteristic data D2 corresponding to the identification code D1 of the die 2 to be replaced is read from the data storage section 6, and the characteristic correction section 7 outputs the detection signal Sd from the pressure sensor 3. The characteristics of the processing system 5 to be processed are corrected. The correction in this case is, for example, gain correction and zero correction.

The correction principle is as follows. Since the output characteristic of the pressure sensor 3 is represented by the general formula y = ax + b, it is possible to match the output characteristics of a plurality of different pressure sensors by a gain correction for a and b correction for zero. Therefore, the characteristic data (a, b) of the pressure sensor 3 is measured in advance, the measured characteristic data is stored, and the characteristic of the processing system 5 that processes the detection signal Sd at the time of die replacement is compared with the characteristic data (a, b). By performing the correction (gain correction and zero correction) according to b), it is possible to correct characteristic variations among different pressure sensors 3.

As described above, even if a different pressure sensor 3 is connected to each strain gauge amplifier in the processing system 5 every time the mold 2 is replaced, processing is performed based on the characteristic data D2 stored in advance. The characteristics of system 5 are automatically corrected.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, preferred embodiments according to the present invention will be described in detail with reference to the drawings.

First, in order to clarify the present invention, the overall schematic configuration of the injection molding system IS will be described with reference to FIGS.
Will be described with reference to.

In FIG. 3, IS is an injection molding system, which includes an injection molding machine M. The injection molding machine M is provided with a machine base 11 at the bottom, and the mold clamping device 1 is mounted on the machine base 11 from the left side.
2, a mold 2, and an injection device 13 are provided respectively.

The mold 2 has a pressure sensor 3 shown in FIG.
Is incorporated. The pressure sensor 3 is a pressure conversion element using a crystal element or the like, and the pressure receiving surface 3p thereof is the mold cavity 2
Place it facing the inner surface of c. Furthermore, a wiring space 2s is provided inside the mold 2, and the pressure sensor 3 is connected to the inlet side connector 3b through a connection cord 3a arranged in the wiring space 2s. The connector 3b is exposed to the outer surface of the mold 2. Therefore, when the mold is replaced, it is connected to the outlet side connector 3c from the strain gauge amplifier incorporated in the controller 14 described later.

On the other hand, a controller 14 is arranged on the machine base 11 of the injection molding machine M and is connected to the molding machine management computer 15, and this molding machine management computer 15 is L.
It is connected via an AN system U to a host computer 16 that performs system control and production management.

On the other hand, the injection molding machine M includes a take-out device 17, a purge receiver 18, a product stocker 19, an automatic die changer 20,
The material stocker 21 is connected to each other, a preliminary temperature controller 22 is connected to the automatic die changer 20, and a bar code reader 23 is connected to the material stocker 21.
Furthermore, the controller 14, the automatic mold changer 20 and the material stocker 21 in the machine base 11 are connected to the host computer 16 via optical communication lines 24, 25 and 26, respectively.

Next, the structure of the mold exchanging device 1 of the injection molding machine according to the present invention will be described with reference to FIG.

The mold exchanging apparatus 1 according to the present invention functions as a part of the automatic mold exchanging machine 20. A data storage unit 6 has a function of storing the identification code D1 of the mold 2 and the characteristic data D2 of the pressure sensor 3 incorporated in the mold 2. The data storage unit 6 is a molding machine management computer 15
You can use the built-in memory. Reference numeral 7 denotes a characteristic correction unit, and the characteristic correction unit 7 processes the detection signal Sd from the pressure sensor 3 based on the characteristic data D2 read from the data storage unit 6 when the mold is replaced. It has a function to correct the characteristics of. The characteristic correction unit 7 is, for example,
It can be provided between the pressure sensor 3 and the controller 14 (with a built-in strain gauge amplifier).

Next, the function of the mold exchanging apparatus 1 including the mold exchanging method according to the present invention will be described with reference to the drawings.

First, as shown in FIG. 3, the pressure sensor 3 incorporated in the mold 2 is connected to the molding machine management computer 15 in advance, and the characteristic data D2 of the pressure sensor 3 is measured. Then, the measured characteristic data D2 is stored in the data storage unit 6 together with the identification code D1 of the corresponding mold 2. The characteristic data D2 is y = ax +, which is the above-described general formula.
Output characteristics a represented by b (gain correction data), b
(Data for zero correction).

On the other hand, when the mold is replaced, the characteristic data D2 corresponding to the identification code D1 of the mold 2 to be replaced is read from the data storage section 6. Then, the read characteristic data D2 is transferred from the molding machine management computer 15 to the controller 1
It is transferred to the characteristic correction unit 7 provided on the fourth side, and the gain correction and the zero correction are performed on the characteristic correction unit 7. Therefore, for one strain gauge amplifier in the processing system 5,
Even if a different pressure sensor 3 is connected each time the mold 2 is replaced,
Since the characteristics of the processing system 5 are automatically corrected based on the characteristic data D2 stored in advance, variations in characteristics among the different pressure sensors 3 ... Can be corrected.

The embodiment has been described in detail above.
The present invention is not limited to such an embodiment.
For example, although the case where the sensor is a pressure sensor has been illustrated, the same can be applied to other sensors such as a temperature sensor. Further, although the embodiment has shown the case where data is stored and controlled using the molding machine management computer, a controller provided in the injection molding machine may be used instead of the computer. In addition, the detailed configuration, shape, method, and the like can be arbitrarily changed without departing from the scope of the present invention.

[0025]

As described above, the method of exchanging a die for an injection molding machine according to the present invention measures and measures the characteristic data of a sensor incorporated in the die in advance when exchanging the die in the injection molding machine. A process of storing the characteristic data and the identification code of the mold incorporating the sensor of this characteristic data, and processing the detection signal from the sensor based on the characteristic data corresponding to the identification code of the mold to be replaced when the mold is replaced. Since the characteristics of the system are corrected, it is possible to easily realize automatic die replacement in an unmanned factory, etc., and it is possible to achieve remarkable cost reduction, high control accuracy, simplification and miniaturization of die construction. Has a remarkable effect.

Further, the mold exchanging apparatus for the injection molding machine according to the present invention includes a data storing section for storing a die identification code and characteristic data of a sensor incorporated in the die, and a data storing section for exchanging the die. Since a characteristic correction unit that corrects the characteristic of the processing system that processes the detection signal from the sensor is provided based on the read characteristic data, there is a remarkable effect that the mold replacement method can be carried out easily and reliably. .

[Brief description of drawings]

FIG. 1 is a block configuration diagram showing a main part of a mold exchanging device according to the present invention,

FIG. 2 is a vertical sectional view of a mold,

FIG. 3 is an overall schematic configuration diagram of an injection molding system including the mold exchanging device,

[Explanation of symbols]

 M injection molding machine 1 mold change device 2 mold 3 pressure sensor 5 processing system 6 data storage unit 7 characteristic correction unit D1 identification code D2 characteristic data Sd detection signal

Claims (6)

[Claims] 1. When replacing a mold in an injection molding machine, characteristic data of a sensor incorporated in the mold is measured in advance,
Stores the measured characteristic data and the identification code of the mold incorporating the sensor of this characteristic data, and at the time of mold replacement, processes the detection signal from the sensor based on the characteristic data corresponding to the identification code of the mold to be replaced. A method for exchanging a mold for an injection molding machine, characterized in that the characteristics of a processing system to be corrected are corrected. 2. The mold replacement method for an injection molding machine according to claim 1, wherein the correction includes gain correction and zero correction. 3. The method of exchanging a mold for an injection molding machine according to claim 1, wherein the sensor is a pressure sensor. 4. A mold exchanging device for an injection molding machine for exchanging a mold in an injection molding machine, and a data storage section for storing a mold identification code and characteristic data of a sensor incorporated in the mold, and a mold exchanging process. A mold exchanging device for an injection molding machine, comprising a characteristic correcting section for correcting the characteristic of a processing system for processing a detection signal from a sensor based on characteristic data read out from a data storage section. 5. The mold exchanging device for an injection molding machine according to claim 4, wherein the characteristic correcting section has a gain correcting function and a zero correcting function. 6. The mold exchanging device for an injection molding machine according to claim 4, wherein the sensor is a pressure sensor.